In her long career as an oceanographer, Sylvia Earle has witnessed the damage that humanity has done to the Earth’s oceans. But in an interview with Yale Environment 360, she says there’s still time to pull the seas back from the brink.
For nearly half a century, Sylvia Earle has been exploring the world’s oceans, taking part in more than 400 expeditions and spending thousands of hours under the sea. An explorer-in-residence at the National Geographic Society and former chief scientist at the National Oceanic and Atmospheric Administration, Earle has broken many barriers in the world of deep-sea exploration.
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Now, drawing on decades of oceanographic work, Earle has written a book in which she reflects on the profound changes she has witnessed in the world’s oceans and offers her thoughts on how to restore the health of a badly over-taxed marine environment. In The World is Blue, Earle describes the two-pronged assault on the seas: what we are pulling out of the oceans, through unfettered industrial fishing, and what we are putting into the oceans through pollutants, fertilizers, and growing amounts of carbon dioxide that are leading to a dangerous acidification of the sea.
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e360: I wanted to talk about what is increasingly looming as this great problem of the acidification of the oceans, the changing chemistry.
You point out in your book that by pulling all these fish out of the ocean, that we actually are affecting the oceans’ buffering capacity to absorb carbon dioxide. Could you explain how over fishing can play a role in the ocean’s ability to absorb carbon dioxide?
Earle: We need a great deal more in the way of exploration, of doing the calculations, but it is simple. This is a no-brainer. Fish, every living thing, is a carbon container. By extracting millions of tons of ocean wildlife, it’s like clear-cutting forests. You have removed the carbon-based units.
But this destruction of the great ocean food web, the destruction of the habitats in the sea, the dredging, the trawling, that [alters] these finely tuned systems that have developed over literally hundreds of millions of years… We call it the great green engine that generates oxygen and takes up carbon dioxide at a point that is just right for life. But our actions in just a little slim period of time have so altered the nature of nature.
You have to think pretty hard about what we are doing and change our ways. And part of it relates to what we are doing to the sea, what we are taking out — the carbon based units that we are removing and the structure of the ecosystem in the seas that holds the planet steady.
e360: And then of course, [we are] pouring all of this CO2 onto the atmosphere, which is absorbed by the oceans. You write in your book that almost half of CO2 emitted every year by human activities is absorbed in the oceans. How concerned are you that we are so rapidly changing the chemistry of the sea that we could reach a point where we could see no mollusks, no shellfish, the loss of most of the world’s coral reefs?
Earle: Scientists who have been looking at the devastation of coral reefs around the world are convinced that we are on the track that leads to that, but it doesn’t have to be that way. Part of that relates to our complacency about carbon dioxide in the atmosphere, our complacency about global warming.
Carbon dioxide is part of the problem, but part of this story is the methane, which is a far more powerful greenhouse gas… A major concern in the minds of many who understand the amount of frozen methane in the deep sea is that the release of that could overwhelm all the other problems that we now face.
We have a little window of time. It’s not too late. We still have maybe half of the coral reefs around the world. They are still in pretty good shape. We haven’t killed the last whale. We still have icecaps at both poles.
But if we continue on the track that we currently are following, we will see within our lifetime, certainly within the lifetime of our children and our grandchildren, changes that will lead to a world that won’t work as well as the world that we now have. We have a chance, but the longer we wait the harder it is going to be.
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Yale University News, 12 October 2009. Full article.
